Considerable advances have been made during the last decade in the treatment of patients requiring maxillofacial protheses. These protheses allow patients to assume a more normal role in society rather than suffering from fear and disfigurement. The materials available to the prosthodontist today are vastly improved over those that were used for many years. However, problems such as color matching a prosthesis to match the patients skin color and discoloration of prostheses as a function of time and use continue to be a detriment in treating these patients. Recent research has pinpointed the causes of clinical failure and identified methods to prevent them. This research should now be expanded and directly applied to the treatment of patients in order to determine the efficacy for widespread clinical use. Specifically, the objectives of this proposed research are: (1) to use a spectrophotometer and a computer program to quantitatively select the proportions of maxillofacial elastomers and pigments to accurately duplicate the skin color of patients, (2) to refine and implement techniques and materials used for extrinsic characterization of maxillofacial prostheses which are predictable, efficient and color stable, (3) to refine the method of solvent extraction of environmental stains from maxillofacial elastomers and apply this technology to the treatment of patients whose prostheses have become stained in use, (4) to determine selected properties of facial tissues in order to modify or select maxillofacial elastomers which will mimic the tissues they are replacing, and (5) to continue to test the physical properties and color stability of new materials and pigments as a function of accelerated aging in order to predict potential for clinical success. The refinement and clinical application of these research efforts will have a profound effect upon the successful treatment of maxillofacial patients by simplifying the methods used to construct prostheses and extending their useful time in service.